let h= history books
science books = s
h=2s there are 2 times as many history as science so to get them equal we double the science
h+s=81 there are 81 total history and science books
2s+s=81 substitute 2s for h in the above equation
3s = 81 combine like terms
s = 27
There are 27 science books
h=2s
h=2(27)
h=54
there are 54 history books
Answer:
$4
Step-by-step explanation:
12÷4=3
7÷7=1
3+1=4
therefore she spent 4 dollars
Answer:
-5 =x
Step-by-step explanation:
f(x)=x+5
Set the function equal to zero
0 = x+5
Solve for x
-5 = x+5-5
-5 =x
<span>2m^2n^4/6m^5n^3
n
= --------
3m^3</span>
